Duan Jiaze inherited a private zoo and was forced to sign a contract after his graduation. And from that day onwards the first ever age classified Luya zoo appeared, those aged under 21 are prohibited to enter. (Source: Twitter User Xiyoumiyu)

A young girl named Tomoko visits the Hiroshima Peace Memorial. There she has a mysterious meeting with Sadako, the little girl who was 2 years old when the U.S. dropped the bomb on her city during WWII and 11 when she died from the effects of radiation poisoning. Sadako takes Tomoko on an eye-opening journey.

The story takes place in a trading city Ert'Aria. Leicester Maycraft is an item engineer belonging to an adventurer guild "Oasis." One night, he is at a party with his friends to see a meteor stream on the rooftop of a chapel. One meteor grazes them and hits the steeple of the chapel. There he finds a secret room and a sleeping girl. The girl wakes up and says "You must be my father!" The encounter with the mysterious girl brings an unexpected adventure to Leicester.

For high school students like Shouichi Kamita, university entrance exams and the future are common concerns. It is also during this time in life that a mysterious emotion that vexes people of all ages may begin to weigh upon one's mind—love. At this point in his teenage years, Shouichi finds three girls he could see himself having a future with: the ever-cheerful Hikari Tsuneki, who teases Shouichi without mercy, but actually has a softer side; the competitive gamer, Tooru Miyamae, who has difficulty communicating with others; and Shouichi's childhood friend, Kyouko Touno, the sometimes immature shoujo manga enthusiast. Seiren follows Shouichi's relationships with these three girls across three separate arcs, as their feelings grow from mutual interest and blossom into something more beautiful. [Written by MAL Rewrite]